1. Field of the Invention
The invention relates to a switch for a sorting device, which switch comprises at least one vane for directing the flow of items to be sorted in the desired direction, which vane is movable by means of a driving device in a direction transversely to the flow of items to be sorted.
2. State of the Art
A switch of the aforesaid type is known from the U.S. Pat. No. 3,027,830. This specification discloses a switch of the above-mentioned sort, which forms part of a sorting device for postal articles, such as letters and the like. In this sorting device the postal articles to be sorted are led from an inlet store along a recognition system, where certain characteristics of the postal articles led along are scanned and processed, after which the postal articles are supplied to a switch, which consists of a pair of vanes, rotatable around two parallel shafts, and each capable of taking up two discrete rotational positions, due to which this known switch has three outlets. Each of these outlets opens into into an outlet store. In this case the positions of the switch vanes are controlled from the system in which the scanned characteristics of the postal articles are processed. The control of the positions of each of the vanes takes place by means of a pair of coils provided with a sliding core, one end of each of these sliding cores being pivotally mounted on one of the ends of a bridge portion, which is rigidly connected to the relevant vane and can rotate around the same shaft as the vane.
The advantage obtained when using a double-vane switch instead of e.g. a single-vane switch is that with a double-vane switch one or both switch vanes need not undergo more than one change of position for any change into another outlet position (so from outlet 1 to 2, 1 to 3, 2 to 1, 2 to 3, 3 to 1 or from 3 to 2). So it will not at all be necessary to take up an intermediate position, which is the case with a single-vane switch with three outlets (e.g. the change from outlet 1 into outlet 3 takes place via outlet 2).
A drawback of the known switch is that two coil-sliding core-combinations will be needed for operating each of the vanes. Apart from the fact that this is a comparatively expensive solution, which occupies relatively much room, the change-over speed is comparatively low, inter alia because of the relatively considerable mass of the two sliding cores. Moreover, the position of each of the vanes depends on the tensile force of the relevant coil, due to which the positions of the vanes are relatively sensitive to disturbances. Besides an electric current has constantly to flow through one of the coils in any position of each of the vanes, which is also a drawback in view of the cost of energy and the heat dissipation.